Method of recovering oil and gas.



lNl/E/VTUR A TTURIVEYS Patented Sept. 12, 1916.

2 SHEETS-SHEET I F. SQUIRES.

METHOD OF BECOVERING OIL AND GAS.

APPLICATION FILED MMLQ. 191s.

F. SQUIRES.

METHOD OF RECOVERING OIL AND GAS.

APPLICATION FILED MAR.9| I9l6. 1,198,078.

PatentedSept. 12,1916.

2 SHEETSSHEET 2.

WIT/V588 lNl/E/VTUR Q-AM s B ATTORNEYS UNITED STATES PATENT OFFICE.

FREDERICK SQUIRES, OF MARIETTA, OHIO, ASSIGNOR TO WALTER SQUIRES, 0FZANESVILLE, OHIO.

METHOD OF BECOVERING OIL AND GAS.

Application filed March 9, 1916.

T 0 all whom it may concern.

Be it known that I, FREDERICK SQUIRES, a citizen of the United States,residing at Marietta, in the State of Ohio, have invented certain newand useful Improvements in Methods of Recovering Oil and Gas, of whichthe following is a specification, reference being had to theaccompanying drawings, forming a part hereof.

It is now the general practice to recover oil and gas from non fiowingwells by applying pressure to one of several wells drilled to the oilsands and relying on the pressure to vent the oil and gas at certainother wells, which serve as venting wells, drilled to the same sands, orbring it to such wells for pumping to the surface. Usually compressedair is employed and oftentimes suction pumps are used on the ventingwells in conjunction with the compressors on the other wells. In thismethod it is evident that the friction of the sands alone is relied onto maintain a sufiicient pressure at the venting wells to lift the oiland gas to the surface or bring it to the bottom of the wells fromwhence it may be pumped to the surface. In large sand fields, especiallythose of a conglomerate composition, the area of pressure and degree ofporosity are so great as to make it impossible to maintain a pressureadequate for the purpose. Again, it often happens that wells onneighboring leases, drilled to the same sands, are left open, eitherintentionally or after abandonment, so that the pressure applied to suchsands finds a ready release at such open wells and is not effective forthe purpose of forcing the oil and gas to the venting wells provided.Under such conditions, not only is the method wholly ineffective for therecovery of the oil and gas, but it is, in fact, most disadvantageous tothe operator since it actually drives the oil and gas from his leasealong the easier paths to the open wells on neighboring leases.

It is the primary object of the present invention to meet theseobjections to known methods involving the principle stated by providingmeans for presenting the dissipation of the fluid pressure applied tothe sands and further to prevent the oil and gas in the sands beingoperated from flowing to neighboring leases. Incidental to the improvedmethod is a highly advantageous Specification of Letters Patent.

Patented Sept. 12, 1916.

Serial No. 83,011.

way of forcing the oil and gas to the venting wells and maintaining itin the neighborhood of the venting wells until entirely withdrawn. Thislast condition is one which will be recognized as most advantageous, inas much as known methods, where effective in forcing the oil and gas tothe venting well, have made no provision for checking the flow thereofpast the venting well with the result that a large percentage of oil andgas under the pressure medium has been forced beyond the venting well onto neiglr boring leases.

In accordance with the present invention, it is proposed to form in theoil sands a dam of a relatively incompressible fluid, such as water,which dam shall serve, either wholly or in conjunction with theimpervious mineral boundaries of the sands, to enrap the oil and gasover any desired area, 0 that such oil and gas under pressure fromrelatively compressible fluid, such as aiw my be forced to the pumps inor out t irough suitable venting wells located within the included area.This liquid dam may be created by forcing in water under pressure andmay have its area controlled by applying air pressure to each sidethereof through wells provided for that purpose and so may, through thispressure control, be caused to encroach more or less, as may bedesirable, on the oil sands for the purpose of forcing the entrapped oiland gas out through the venting wells. This system which, forconvenience, may be termed a flood pressure system, permits the liquiddam or flood to be used as desired in assisting the compressed air inventing the entrapped oil and gas. Where, as it is often the case, theoil sand is found in a comparatively narrow streak and disposed withinan impervious mineral covering, the improved method will be especiallyuseful in that it permits a dam of liquid to be thrown across this oilstreak adjacent the boundaries of the particular lease which the streaktraverses, so that all of the oil and gas between these boundaries maybe held there and ultimately recovered as by applying air pressurethereto between the liquid dams or by causing the liquid dams toencroach on the oil and gas and so force it from the venting lease. Theinvention is not to be limited in its application to any such condition,

however, as it will also be found useful in large oil tracts in whichthe sands are of unknown extent and outline. In such a field, theadvantage of an impervious mineral boundary on one or more sides of theoil bearing stratum would not be had, but the sands would, as usual, becapped at top and bottom by such an impervious layer of rock. Thepresent method is used in such sands by creating a continuous dam ofliquid in the oil sands, of any desired outline, usually depending uponthe outline of the particular lease being operated. The dam in this instance is maintained by pressure applied to the two sides thereof and,being continuous, is controlled in the manner indicated with respect tothe separate dams described above and as employed in narrow sandstreaks. Still another condition under which the improved method isuseful is one in which a liquid dam is formed near the center of an oillease traversed by a narrow sand streak and air pressure is applied atopposite sides of the dam at points near the boundaries of the lease, sothat oil and gas included in the sands between the dam and the pressurewells is vented through venting wells provided therefor. In this casedifferent pressures may be maintained at opposite sides of the dam andthe latter may be caused to encroach on the oil and gas in one directionor the other as desirable.

The invention will be described in greater detail in connection with aspecific application of the improved method to fields wherein the threesuggested conditions may arise, and as illustrated in the accompanyingdrawings, in which Figure 1 is a somewhat conventional illustration inplan of an oil bearing streak of sand drilled for the practice of theinvention. Fig. 2 is a view in section through the earth and the fieldindicated in Fig. 1 and taken along the plane of the line 2-2 of saidfigure. Fig. 3 is a sectional view somewhat similar to Fig. 2, but takentransversely through the field of Fig. 1 along the plane indicated bythe line 3-3. Fig. 4: is another transverse section through the fieldalong the plane indicated by the line 44 of Fig. 1. Fig. 5 indicatessomewhat conventionally a continuous dam in an oil field in which theimproved flood pressure is to be employed. Fig. 6 is a conventional viewof another condition under which the present method may be usedsuccessfully.

As this description proceeds, it will be made plain that the improvedmethod is not to be limited in its application to oil hearing strata ofany particular outlines, nor to oil sands having peculiar localconditions. It may be practised, in principle, under any circumstanceswhere it is desired to create some means for limiting the free flow ofoil and gas in any direction, through the sands, and for preventing thedissipation of the air pressure applied to such sands for the purpose ofventing such oil and gas. For instance, by reference to Figs. 1 and 2,it may be supposed that the sand streak traversing the particular leaseto be oper: ated is of some such outline as is shown in Fig. 1 and thatthe impervious rock walls at the sides of the lease converge at certainportions, as will be later described. In accordance with the presentmethods, pressure wells a would be drilled to the oil bearing sands andpressure applied through such wells to vent the oil and gas through theventing wells 6 located at the most advantageous points. It is quiteevident that whether these venting wells I) be located be tween thepressure wells at or outside of them, or whether the sands be relativelydense or not, the waste of effective pressure is necessarily great sincethe pressure may find an outlet longitudinally of the narrow streak indirections away from the venting wells Z), as well as through saidwells. here the sands are relatively porous, as is the case when theyare of a conglomerate composition, it is often impossible to maintain asuflicient pressure on the wells at to carry the oil to the pumps in orto lift the oil and gas through the venting wells 1), so that the leaseremains unworked. Again, where the owners of neighboring leases drillwells to the same sands and leave them open, the pressure applied at thewell a will find ready escape through such wells and bring about, oftentimes, a liberal discharge of oil and gas on the neighbors property.Again, the ready escape found by oil and gas in such sand strata alwaysresults in the carrying off from the operated lease of a certainpercentage of the oil and gas of which the operator is the owner.

In accordance with the present invention, the highly inefiicient, andoften times ineffective, methods now employed are replaced by meanswhich entrap the oil and gas on the lease operated and permit of itsready recovery. The improved method further eliminates the dissipationof the pressures applied to the sands and augments such pressures byrelatively incompressible fluids, such as water, which may be controlledin such manner as to cause their encroachment upon the oil and gas andassist in their discharge.

For convenience in the description, a concrete case will first beconsidered. Let it be assumed that the lease to be operated, besideshaving its sands in the narrow and irregular streak shown in Fig. 1, hasits boundaries along the lines 0, c, d, d, at the ends of the streak. Bydrilling, it may be determined that the oil bearing sands are contractedat the points x, w, the non-productive wells 6 indicating, withinlimits, the

boundaries of the streak. The wells 7, f, are drilled to the sands alongthe section of the contracted portions of the streak and through thesewells is introduced, under pressure, a suitable relativelyincompressible fluid, preferably water, which saturates the sandsimmediately in the neighborhood of the wells and forms a liquid damacross the contracted sections 00, m. Air pressure is applied to thesands at either side of the dams g, as through the pressure wells at andthe counter-pressure wells it, which latter are drilled outside of thedams. It will be evident that by equall izing the pressures on oppositesides of the,

dams g, the dams may be held against movement and caused to fill thesand stratum from the impervious floor 71 to the impervious roof 2"between which the sand is disposed. By raising the pressure relatively,the oil and gas entrapped between the dams cl and the impervious sidewalls 2' of the oil belt, may be forced readily through the ventingwells 1). The dams and impervious side walls prevent dissipation of theair pressure applied through the wells at so that it may be said thatthe entire pressure is eifective in accomplishing its intended purpose.No matter, how porous the sand in the streak, no difficulty will beexperienced in raising the pressure in the included area sufficientlyhigh to force the oil and gas to the pumps in or actually from theventing wells 6.

As soon as the oil level within the included area drops, the liquid dams9 may be caused to move inwardly toward the venting wells and soencroach upon the oil to be vented, by controlling the relative airpressures on the two sides of the dams or by forcing in more waterthrough the hydraulic wells f. In either event, the oil is held in theneighborhood of the venting wells 5 until entirely removed. It has nooutlet from the included area. No matter what the condition. in thesands on the neighboring leases, the pressures applied through the wellsat will be wholly effective in venting the oil and gas entrapped betweenthe dams (7, g. In bringing about this venting, it will be evident thatthe layers of water and oil disposed within the included area will notfill the impervious casing from the floor 2' to the roof 2'', in whichcase the natural tendency will be for the air to flow under pressurealong the surface of the oil between its level and its roof i and escapethrough the vents. To obviate this condition, the casings of the ventingwalls 7) are extended downwardly into the oil and terminate well belowthe level thereof so that no gas or air can pass out through the easingwithout carrying with it a quantity of oil, owing to the liquid sealeffected. Such liquid seals may also be found at other sec- &

tions of the sand stratum, as indicated at i, where the root 1 issomewhat irregular and projects downwardly into the layer of oil. Thiscondition is helpful in bringing the air pressure to bear on the oil.

Under the conditions illustrated in Fig. 5, it may be supposed that theoil sands are of unknown area and outline and that the lessee of aportion of such sands desires to remove the oil and gas from hisholdings without forcing them on to neighboring leases and withoutwasting the compressed air by relying only on the friction of the sandsto maintain the pressures. In this case, hydraulic wells F are placedaround the wells to form an included area of any desired outline(rectangular in the illustrated embodiment) and a continuous dam G isformed in the sands which is maintained, as described with reference tothe preceding figures of the drawings, by applying pressure on bothsides thereof, as through counter-pressure wells H and in cludedpressure wells A. The pressure applied through the included wells Aserves to vent the oil and as through the venting wells B which may bedisposed at suitable points. As the oil and gas are vented, it may bedesirable to cause the dam G to contract relatively so as to encroach onthe sands and assist the pressures thereon in venting the oil and gas.This encroaclr ment may be effected in the manner heretofore described.

In Fig. (5 is illustrated another possible application of the method, inwhich a dam Gr is formed transversely of the oil hearing sand streak andat about the mid-section thereof, in the manner before described, andpressure wells A are drilled adjacent the outer ends of the streak andthe oil and gas included between the pressure wells and the liquid dam Gvented as through venting wells 13*. The dam Gr in this instance may bemoved relatively through the sand streak to cause the encroachmentbefore re ferred to for the purpose of augmenting the pressures andassisting in the venting of the oil and gas.

It is possible in this specification only to describe a few of theconditions under which the method will be especially useful, but it hasbeen sought to emphasize throughout that there is involved an improvedprinciple on which the steps of the method are based and that theinvention is not to be limited to the concrete applications shown in thedrawings.

Reference is to be had to the appended claims for a definition of thescope of the invention.

I claim as my invention:

1. The method of recovering oil and gas which consists in forming aliquid dam under pressure in the oil bearing sand to prevent the escapeof the entrapped oil and gas, and applying pressure independent of theliquid to said oil and gas to vent them.

2. The method of recovering oil and gas which consists in forming aliquid dam in the oil bearing sand to prevent the escape of theentrapped oil and gas, and creating a pressure differential on the damby applying independent pressures at opposite sides thereof to cause itto encroach on the oil hnd gas under the control of the operator.

3. The method of recovering oil and gas which consists in forming aliquid dam in the oil bearing sand to prevent the escape of theentrapped oil and gas, applying pressure to the opposite sides of thedam to maintain it, and creating a pressure differential on the dam bvapplying independent pressures at opposite sides thereof to cause it toencroach on the oil and gas under the control of the operator.

4. The method of recovering oil and gas which consists in forming aliquid dam under pressure in the oil bearing sand to prevent the escapeof the entrapped oil and gas applying pressure to the opposite sides ofthe dam to maintain it, applying pressure to said entrapped oil and gasto vent them, and creating a pressure differential on the dam to causeit to encroach on the oil and gas under the control of the operator toassist in the venting.

5. The method of recovering oil and ga which consists in drillingpressure and venting Wells to the oil bearing sands, sinking a casing inthe ven ting Wells with its end below the oil level to 'form a liquidseal and applying pressure to the surface of the oil through thepressure Wells.

This specification signed this third day of March A. D., 1916.

FREDERICK SQUIRES.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. G.

